1. Field of the Invention
This invention relates to a valve for controlling flow between a region exterior of a tubular member and a region interior of a tubular member.
2. The Prior Art
Sleeve valves, such as illustrated on pages 3966 and 3967 of the 1974-75 edition of the "COMPOSITE CATALOG OF OILFIELD EQUIPMENT AND SERVICES" have been utilized to control flow through lateral ports. However, axial movement of the sleeve valve mandrel is resisted by frictional forces between the seals and the housing. For some laterally ported installations, the frictional resistance to axial movement of the sleeve valve mandrel cannot be tolerated. A much more easily movable valve mandrel is required.
Tubular packings, as disclosed in U.S. Pat. Nos. 3,215,208; 3,036,639; and 2,988,148 have been utilized to seal an annulus between concentric pipe and prevent longitudinal fluid flow through the annulus. The tubular packings must be compressed and expanded into engagement with the outer pipe before they are effective to seal off the annulus.
Cup-type packing elements, as disclosed in U.S. Pat. No. 2,988,148, have also been used to seal the annulus between concentric pipe. A cup-type packing element can function as a check valve permitting longitudinal flow through the annulus in one direction and preventing longitudinal flow through the annulus in the other direction. However, a cup-type packing element would quickly loose its sealing capabilities if operated as a sliding valve.
U.S. Pat. No. 2,642,889 and page 3917 of the "COMPOSITE CATALOG OF OIL FIELD EQUIPMENT AND SERVICES", 1970-71 edition disclose a valve having a cup-like packing element to function as a check valve and prevent back flow through a lateral port and a tubular packing element which is radially expandable to prevent flow through the lateral port. Expansion of the tubular packing element is controlled by adjusting the pressure of a confined charge of flow relative to the pressure of fluid against which the packing element is sealing. The higher the pressure against which the disclosed tubular packing element must seal, the weaker the seal. If the pressure against which the disclosed tubular packing element is sealing is greater than the pressure of the charge of fluid, the seal is broken and fluid flow is permitted through the lateral port.